The Subnetwork Connection Protection (SNCP) is an important protection type of a transport network. It may be a partial connection of the transport network or may be extended to an end-to-end connection of the transport network. Based on the different monitoring modes of a failure, the SNCP may be generally divided into Inherently monitored SNCP (SNC/I), Non-intrusively monitored SNCP (SNC/N) and SNCP with Sublayer monitoring (SNC/S).
The Transport Multi-Protocol Label Switching (T-MPLS) network is a packet transport network, and the SNCP may be used for guaranteeing that the traffic is able to be rapidly switched to a backup path when a working path of the T-MPLS fails.
A general linear protection switching mechanism is specified in International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) recommendation G.808.1. At present, a relevant protection standard for the T-MPLS network is laid down in G.8131. However, no solution about how to implement the SNCP in the T-MPLS network is put forward yet.